8th Investigation 5 Acceleration
In Acceleration students are introduced to acceleration as changing velocity and learn ways to determine acceleration from displacement and time data.
Part 1-Comparing Tracks A and B
Students experience the distinction between constant velocity and acceleration. They are presented with two tracks with flags to indicate where a traveler on a track should be at 1-second intervals.
Students are challenged to travel along the tracks, hitting marks (positions) as the teacher calls out the seconds, up to 8 seconds. To hit each mark exactly on one track students have to move at a constant .5 m/s. To hit the marks on the other track students must accelerate at .5 m/s2.
Part 2-Rolling Dot Car
Students address the question, Do cars roll down ramps at a constant velocity or accelerate? To find out, students use a mechanical dotcar, a rolling car that makes an ink dot on paper every half second. They roll the dotcar down ramps and study the dots.
Students extract, organize, process, and graph the data for analysis. They interpret the resulting graph to determine that the velocity of the rolling Dotcar is continuously changing, and the steeper the ramp, the faster the car accelerates.
Part 3-X and Z Car part A and B (Dots in Motion)
Students study a scenario involving dot patterns left by two cars. They measure, organize, graph, and interpret data points to determine velocity and acceleration.
Part 4-Dotmaker A and B
Students use the online Dot Maker program to analyze various video motion events. The program lets them place dots on the video in order to extract position and time data from the action. They graph and interpret the motion seen in the videos.
Part 5-Cars and Loads A and B
Students investigate how mass affects the acceleration of a rolling car. They use the electronic Dotcar to acquire data from an unloaded car and loaded car rolling down the same slope. Data are recorded electronically and transferred to a computer for organization and display. The data are then graphed. Students find that the variable of mass has little effect on acceleration.
